The present invention relates to an improved annular seal assembly to be utilized for sealing across the annulus between the interior of a wellhead housing and the exterior of a hanger positioned within the wellhead housing.
Prior wellhead annular seals have included resilient seals which are actuated into sealing position by axial force exerted on the seal ring. (U.S. Pat. No. 2,920,909)
Other wellhead seals have included resilient material with metal end members having lips which when the seal is set engage the sealing surfaces to prevent extrusion of the resilient material as shown in U.S. Pat. No. 3,797,864.
Other annular wellhead seals have wedging elements to wedge the seal legs into sealing engagement with its sealing surfaces after the seal has been properly positioned with respect to such sealing surfaces. This structure is shown in U.S. Pat. Nos. 4,131,287 and 4,595,053. This latter patent also discloses the use of wickers or small parallel grooves into which the seal is forced for sealing.